This application is based on and claims the priority under 35 U.S.C. xc2xa7119 of German Patent Application 100 33 093.2, filed on Jul. 7, 2000, the entire disclosure of which is incorporated herein by reference.
The invention relates to a clamping mechanism for releasably interconnecting structural components having a rotational symmetry such as cylindrical or conical bodies, for example for connecting a payload to a carrier rocket. The clamping mechanism forms a tensioning ring which must be capable of releasing one structural component from the other structural component without completely opening the ring.
Clamping devices that surround the components to be releasably interconnected are known in the art. Hose clamps come to mind. These clamps surround the components in a clamping or tensioning plane. Certain of such devices comprise clamping elements arranged along the radially inwardly facing side or inside of a tensioning member. The clamping elements have a radially inward facing contour, that cooperates with a respective radially outward facing flange type contour of the structural components to be interconnected. At least one tensioning member in the form of a strap, belt, tape or cable is provided with one eye at each end. A journal bolt passes through one eye and connects the respective strap end to a tensioning device. A further journal bolt passes through the other eye and is also connected to the tensioning device. When the tensioning device is operated to tension the tensioning member the two journal bolts move toward each other thereby tensioning the tensioning member around the two components whereby the two components are releasably interconnected. The tensioning device conventionally separates the ends of the tensioning member completely from each other.
German patent publication DE 37 27 448 C2 describes a tensioning device as described above. Such a tensioning device is particularly used in space technology in order to connect a payload to an end stage of a carrier rocket. When the target orbit is reached the payload is separated and released from the carrier rocket by opening the tensioning device to thereby completely open the device.
German patent publication DE-OS 26 55 772 describes another tensioning device useful for the above mentioned purposes of separating a payload from a carrier rocket. The tensioning device is known as a xe2x80x9cMarmansxe2x80x9d tensioning connector. Just as in the first mentioned conventional tensioning device, the xe2x80x9cMarmanxe2x80x9d tensioning connector is also provided with clamping elements on the inner surface of a tensioning belt or strap. The tensioning devices are provided on their radially inwardly facing surface with conical recesses which cooperate with correspondingly shaped flanges of interface rings of the structural components to be interconnected. These flanges of the interface rings are secured to the end sections of the structural components to be is interconnected. The tensioning device holds the ends of the tensioning strap together when the two structural components are interconnected. The clamping elements are separated or pulled off by a pyrotechnically controlled explosion whereby the structural components separate from one another, for example a payload is separated from the carrier rocket end stage.
Even though the explosion is pyrotechnically controlled, it is unavoidable that the sudden separation of the tensioning member suddenly releases a high tension energy that was stored in the tensioning member such as a strap. As a result, under certain circumstances it is possible that a relatively strong shock load is applied to neighboring components and systems of the rocket and/or the payload.
In view of the foregoing it is the aim of the invention to achieve the following objects singly or in combination:
to construct a tensioning assembly for a strapping apparatus or clamping mechanism of the type described above in such a way that the drawback of a sudden tension release is avoided when the tensioning assembly of the strapping apparatus is opened or released;
to assure that a trouble-free, constant, uniform radially inwardly directed clamping tension is applied along the entire circumference of the structural components to be interconnected;
to construct the tensioning assembly in such a way that a controlled radial opening notion which increases the diameter of the tensioning member is achieved without completely opening the clamping mechanism;
to release the tension in the tensioning member, such as a strap, and in the tensioning assembly gradually and without completely separating the ends of the tensioning member from each other; and
to construct the tensioning assembly in such a manner that a controlled radially directed opening motion of one or more tensioning straps is assured.
The above objects have been achieved in the strapping apparatus also referred to as clamping mechanism according to the invention in that the ends of one or two tensioning members such as straps, belts, tapes or cables are interconnected by at least one tensioning assembly that includes two tensioning levers and a locking mechanism. Each tensioning assembly has two spaced and hinged tensioning levers which carry journal bolts passing through eyes at each end of the tensioning member or members. Preferably an end of each tensioning lever is hinged to a fixed point on a mounting provided in common for both spaced and hinged tensioning levers. Locking elements of a locking mechanism are provided on the common mounting for locking the spaced and hinged tensioning levers in their tensioned position. The two spaced and hinged tensioning levers are tilted toward each other for applying tension to the tensioning member to thereby interlock the two structural components. The spaced and hinged tensioning levers are tilted away from each other to open the strapping apparatus. Several tensioning assemblies and locking mechanisms may be distributed around the circumference of the strapping apparatus.
When the present strapping apparatus is opened by tilting the spaced and hinged tensioning levers around their separate hinges and away from each other, a clamping ring formed by the tensioning member, by the tensioning assembly and by the locking mechanism is merely enlarged in its diameter without completely separating the ends of the tensioning member. As a result, opening the present clamping ring first transforms the stored energy of the closed status into motion energy and then into elastic energy which is taken up by the tensioning member and is not imposed on neighboring structural components. The length of the opening motion of the present strapping apparatus can be reduced by distributing several belt clamps around the circumference of the circular clamping plane of the structural components. Such belt clamps limit the motion of the tensioning member or members, especially the radially outwardly directed opening motion thereof. These belt clamps locally control the strapping apparatus so that a sudden jumping of the strap ends is avoided.